Storage apparatus, such as a mass hard disk drive, are used for the apparatus for industrial ways which perform real-time distribution in the video contents memorized by the video server and the like.
This kind of apparatus needs to complete writing and read-out of data to a storage apparatus to within a time which is defined according to a system. That the time which the writing of data takes, and the time which read-out of data takes exceed the set time may cause interruption of video and audio.
Although hard disk drives are large capacity and low cost, they have difficulty in respect of speed and reliability. Therefore, a solid-state disk (“SSD” is called hereafter) has come to be used by the system of an industrial way as a high-speed storage apparatus in recent years.
The SSD used by the system of an industrial way is expensive if capacity becomes large. For this reason, to use general-purpose SSD at a low price connectable with the general-purpose interface of serial ATA and the like is required.
Since the delay time of writing and read-out are not guaranteed to storage apparatus, such as general-purpose SSD, delay may produce information processing apparatus in data processing. For this reason, storage apparatus, such as general-purpose SSD, cannot be used for the apparatus which performs real-time control with that state.
In recent years, the technology of guaranteeing the response time about the writing to the disk in a storage apparatus is developed by performing mirroring using two I/O buffers and two disks (for example, JP patent disclosure No. 2016-227923). By the way, since the same data as two disks will be written-in the case of such technology, when two disks approach a life at the same time, it is necessary to exchange both of disks at the same time. As a result, the period which cannot use a storage apparatus arises.